Coal mining machine with collapsible head



April 5, 1955 J.- 5. ROBBINS 2,705,624

COAL MINING MACHINE wrm COLLAPSIBLE HEAD Filed Jan. 4, 1952 3Sheets-Sheet 1 A INVENTOR. JAMES S. ROBBINS ATT'YS April 5, 1955 J. 5.ROBBINS 2,705,624

COAL MINING MACHINE WITH COLLAPSIBLE HEAD Filed Jan. 4, 1952 3Sheets-Sheet. 2

FIG-2 INVENTOR. JAMES S. ROBBINS BY W ATT'YS April 5, 1955 J. s. ROBBINS2,705,624

COAL MINING MACHINE WITH COLLAPSIBLE HEAD Filed Jan. 4, 1952 3Sheets-Sheet 3 IN V EN TOR.

JAMES s. ROBBINS BY United States Patent 2,705,624 COAL MINING mommaCOLLAPSIBLE James S. Robbins, Highland Park, 11]., assignor to GoodmanManufacturing Company, Chicago, 111., a corporation of IllinoisApplication January 4, 1952, Serial No. 264,880

Claims. (Cl. 262-7) This invention relates to mining machines of thegeneral type which cuts circular kerfs in a rock mass and breaks downthe cores between such kerfs.

The main objects of this invention are to provide an improvedconstruction for the cutter-carrying parts of such mining machineswhereby the cutting tools are readily displaced from their operativepositions to increase the maneuverability of the machine when required.

A specific embodiment of this invention is shown in the accompanyingdrawings in which:

Figure 1 is a side elevation of some of the essential parts of a coalmining machine constructed according to this invention.

Fig. 2 is a sectional detail taken on the line 2-2 of Fig. 1, showingthe contour of the tunnel that is cut by the machine and showing therotary cutters in front elevation and omitting the parts of the machinethat would appear in the background.

Fig. 3 is a section taken on the line 3-3 of Fig. 1 showing parts of themachine that are related to the cutters of chain-type that are used inthe machine, with the paths of the chain-type cutters indicatedschematically by broken lines.

Fig. 4 is a detail of a suitable form of cutter chain.

The machine shown in the drawings is of the McKinley type in which themain frame 11 is mounted so as to travel forward as by means of atractor mechanism 12 of the track-laying type, driven by appropriatemechanism not forming part of the present invention, that caaririies therock-cutting tools forward against a rock w The machine shown comprisesa pair of power shafts 13 that are journaled on the frame 11 and motordriven. The shafts 13 are disposed side-by-side in parallel relation toeach other and to the direction of travel of the machine and each shaft13 carries at least a pair of oppositely extending radial arms 14carrying cutters 15 disposed so as to cut circular kerfs in the rockwall toward which the machine is advancing. Each of the shafts 13carries at its forward end a pilot bit 16 that penetrates the rocksomewhat in advance of the cutters 15.

Behind the pilot bit 16, the shaft has mounted thereon a conical breakermember 17 adapted to exert wedging pressure on the walls of the borethat is formed by the pilot bit to break down the annular core of rockthat stands between the circular kerf cut by the cutters 15 and the boreof the pilot bit. It will be understood that the cutter carrier arms 14might have additional cutters spaced apart radially along the length ofthe carrier arms but for the purpose of disclosure of the presentinvention, it is sufficient to show merely the cutters that are at theextremities of these carrier arms.

The two shafts 13 are spaced apart horizontally so that the circularcontours 18, Fig. 2, which represent the paths of the cutters 15, willoverlap, as shown in Fig. 2. In order to cut off and break down thecores that lie along the floor and roof of the tunnel between the kerfsthat are cut by the cutters 15, the machine is equipped with a system ofchain-belt cutters located immediately behind the rotary cutters.

In the form shown, there are two such chain-type cutters; an upper one,indicated by the broken line 19, being arranged to cut away the mass ofcoal that would otherwise stand at the roof, and a lower one,represented by the broken line 20 in Fig. 3, being arranged to cut awaythe mass of rock at the lower level.

The upper cutter chain 19 is supported by an elongated guide channel bar21 which is positioned to guide the portion of the chain which makes thecut that forms the roof 22 of the tunnel between cuts made by the rotarycutters. The lower cutter chain 20 is similarly guided by a straightchannel-shaped guide bar 23 that guides the chain 20 at the level of thefloor 24 of the tunnel. As indicated in Fig. 4, the chain comprises aseries of links 20.1 each having a cutter blade 20.2 set into the frontside thereof with alternate blades tilted oppositely to cut a kerfslightly wider than the thickness of the chain and its horizontal guidebar 23.

The guide bar 21 is carried by posts 25 connected to the frame of theguide by pivots 26. The posts 25 are in the form of connecting rods ofthe plungers of hydraulic jacks 27. At each end of the guide 21, thereis journaled a pulley 28 over which the cutter chain passes to apower-driven sprocket 29 by means of which the chain 19 is driven. Thesource of power for driving the sprocket 29 and the chain 19 is notshown in the drawings, being well known in the art and not a part of thepresent invention.

A chain-belt tightening sprocket 30 is journaled on a carrier member 31which in turn is journaled concentrically with the axis of the sprocket29 and is adapted to swing about the axis of the sprocket 29 fortightening the belt 19. The bracket 31 is normally urged by acompression spring 32 and flexible connection 33 so as to exert a propertensioning pressure upon and take up slack in the chain 19.

The chain belt 20 is similarly driven by a power-driven sprocket 34 andis similarly tightened by a sprocket 35 journaled on a member 36 that isin turn journaled concentric with the axis of the sprocket 34 andnormally urged into position for tightening the belt 20 by a compressionspring 37 and flexible connection 38.

The lower guide 23 for the floor cutting portion of the chain 20, in theform shown, is somewhat longer than the upper guide 21 and is rigidlyattached by struts 39 to the frame 11. At each end of the guide member23, there is an extension arm 40 on which a guide pulley 41 isjournaled. These extension arms are pivoted at 42 so as to swingupwardly, as shown at the right of Fig. 3.

Each arm 40 is braced by a pair of toggle links 43 and 44 controlled bya jack 45, for holding the guide pulley 41 in position for guiding thecutter chain 20 during its cutting operation, which position isindicated by full lines in Fig. 3 and this position of the toggle linkscorresponds to the fully contracted condition of the jack 45. When thejack 45 is extended by hydraulic pressure behind its piston, the togglelinks will be shifted to their buckled position, as shown by brokenlines at the right of Fig. 3, raising the pulleys 41 to shorten theportion of the cutter chain that extends across the floor of the tunnelfor the purpose of providing clearance for maneuvering the machine whenthe cutting devices are not in operation. When the pulley 41 is raisedthe chain 20 bends at its nearest joint beyond the end of the guidemember 23.

Each of the carrier arms 14, which drives the circular kerf cuttingcutters 15, is made of two parts rigidly connected end-to-end by areadily separable joint which permits the outermost or tool-carryingportion 46 to be quickly removed when the machine is not in operationfor the sake of maneuverability of the machine along the finished partsof the tunnel.

In the form of joint shown in the drawings, the meeting ends of thefixed portions of the arms 14 and the tool-carrying extensions 46 arestructurally identical but one is inverted with respect to the other,and each comprises a planar meeting surface 47 at right angles to thelongitudinal axis of the arm 14 with a laterally projecting flange 48 atone side parallel with the surface 47 and a hook-shaped flange 49 at theopposite side shaped to overhand the planar meeting surface 47 so as tohave wedging engagement with the flange 48.

The arms 14 and their extensions 46 are rigidly connected by bolts 50that extend between the hooked flanges 49 in the plane of the meetingsurfaces 47, which surfaces of both members 14 and 46 are grooved toreceive the bolts 50, the grooves forming keyseats and the bolts formingkeys that lock the parts together, as described and claimed in mycopending applications, Serial No. 263,339, filed December 26, 1951, nowPatent No. 2,680,034, and Serial No. 151,851, filed March 25, 1950, nowPatent No. 2,587,065.

The machine frame 11 is tiltable with respect to the tractor frames 51,so that the lower chain guide 23 can be raised above the floor of thetunnel after the upper guide 21 has been lowered. To this end the frontpart of frame 11 is raised by jacks 52.

When the machine is in the operation of cutting a tunnel, the parts arein the position shown by full lines in the drawings. For freedom ofmovement of the machine within the tunnel when it is not engaged in theoperation of rock cutting, the extensions 46 of the rotarycutter-carrying arms 14 are disconnected by releasing the bolts 50; theupper cutter chain guide 21 is lowered by releasing the pressure in thejacks 27; the lower cutter chain guide is reduced in its effectivelength across the floor of the tunnel by applying pressure to the jacks45 and thus raising the arms 40 to the positions in which they are shownin broken lines in Fig. 3; and finally the front of frame 11 is liftedby jacks 52 to raise the chain guide 23 up from the floor level.

The machine may then be maneuvered in the tunnel without interference byor danger of damage to the cutting devices.

Although but one specific embodiment of this invention is herein shownand described, it will be understood that numerous details of thestructure shown may be altered or omitted without departing from thespirit of the invention as defined bv the following claims.

I claim:

1. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut circular kerfs respectively concentric withsuch axes in a rock wall transverse to such axes, and a cutter chainmounted on said frame to travel in a straight path on a levelsubstantially tangent to the lower parts of the circular paths of saidrotatable cutters, the improvement comprising a guide roller for saidcutter chain at one end of its straight path, a bearing arm carryingsaid guide roller and pivotally mounted on said frame inward from saidone end of said straight path and swingable to shorten the overall widthof the machine adjacent said straight path of said chain, a togglelinkage connection between said bearing arm and said frame, and meansoperatively connected between said toggle linkage connection and saidframe to fix the positions of said guide roller.

2. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut circular kerfs respectively concentric withsuch axes in a rock wall transverse to such axes, and a cutter chainmounted on said frame to travel in a straight path on a levelsubstantially tangent to the lower parts of the circular paths of saidrotatable cutters, the improvement comprising a guide roller for saidcutter chain at one end of its said straight path, a bearing armcarrying said guide roller and pivotally mounted on said frame inwardfrom said one end of said straight path and swingable to shorten theoverall width of the machine adjacent said straight path of said chain,a toggle linkage connection comprising a pair of links pivoted end toend between said bearing arm and said frame, and a hydraulic jackinterposed between said toggle linkage connection and said frame andoperative to collapse the toggle to swing said guide roller inward.

3. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide mounted on said frame for movement with respect thereto, acutter chain movable along said guide at a level substantially tangentto the circular paths of said rotatable cutters, means operable to movesaid guide with respect to said frame, the improvement in such machinecomprising a guide roller for said cutter chain disposed at one end ofsaid cutter chain guide, and means supporting said guide roller andoperable to shift said guide roller to vary the length of the straightpath of said cutter chain when said cutter chain guide is in theaforementioned position of tangency.

4. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide mounted on said frame for movement with respect thereto, acutter chain movable along said guide at a level substantially tangentto the circular paths of said rotatable cutters, means operable to movesaid guide with respect to said frame, the improvement in such machinecomprising a guide roller for said cutter chain disposed at one end ofsaid cutter chain guide, and means supporting said guide roller andoperable to shift said guide roller up and down with respect to saidguide to vary the length of the straight path of said cutter chain whensaid cutter chain guide is in the aforementioned position of tangency.

5. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide mounted on sald frame for movement with respect thereto, acutter chain movable along said guide at a level substantially tangentto the circular paths of said rotatable cutters, means operable to movesaid guide with respect to said frame, the improvement in such machinecomprising a guide roller for said cutter chain disposed at one end ofsaid cutter chain guide, said guide roller being mounted upon an armsupporting said guide roller and pivotally mounted inward from the endof said cutter chain guide, and means for swinging said arm when thecutter chain guide is in the aforementioned position of tangency.

6. The invention as defined in claim 5 wherein strut means areinterposed between said frame and said arm to brace said arm in itslowered position.

7. In a mining machine comprising a frame and means for driving the sameforward against a rock wall, a pair of rotatably driven shafts mountedon said frame parallel to each other and to the direction of forwardtravel of said machine, radial arms fixed on said shafts, a cutter oneach arm positioned to cut a circular kerf in such rock wall, and cutterchain means on said frame having runs located for cutting horizontalkerfs in the rock wall tangent to the top and bottom portions of thecircular kerfs cut by the cutters on said arms, the improvementcomprising one of said chain runs being bodily shiftable vertically onthe frame away from its normal cutting position, the other said chainrun having elongated guide means with hinged end members shiftableinward to shorten the length of such run, and means whereby the diameterof said radial arms may be changed for reducing the overall height andwidth of the machine for the retraction of same.

8. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide mounted on said frame for movement with respect thereto, acutter chain movable along said guide, means operable to move said guidewith respect to said frame, the improvement in such machine comprisingauxiliary guide means for said cutter chain disposed at one end of saidcutter chain guide, and means supporting said auxiliary guide means andoperable to shift said auxiliary guide means with respect to said cutterchain guide to reduce the length of the straight path of said cutterchain when said cutter chain guide is moved toward the axes of saidrotatable cutters.

9. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide mounted on said frame for movement with respect thereto, acutter chain movable along said guide, means operable to move said guidewith respect to said frame, the improvement in such machine comprisingauxiliary guide means for said cutter chain disposed at one end of saidcutter chain guide, and means supporting said auxiliary guide means andoperable to shift said auxiliary guide means up and down with respect tosaid guide to vary the length of the straight path of said cutter chain.

10. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide mounted on said frame for movement with respect thereto, acutter chain movable along said guide at a level substantially tangentto the circular paths of said rotatable cutters, means operable to movesaid guide with respect to said frame, the improvement in such machinecomprising auxiliary guide means for said cutter chain disposed at oneend of said cutter chain guide, said auxiliary guide means being mountedupon an arm pivotally mounted inward from said auxiliary guide means,and means for swinging said arm when the cutter chain guide is in theaforementioned position of tangency.

11. The invention as defined in claim wherein strut means are interposedbetween said frame and said arm to brace said arm in its loweredposition.

12. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide, a cutter chain movable along said guide at a levelsubstantially tangent to the circular paths of said rotatable cutters,the improvement in such machine comprising auxiliary guide means forsaid cutter chain disposed at one end of said cutter chain guide, andmeans supporting said auxiliary guide means and operable to shift saidauxiliary guide means to vary the length of the straight path of saidcutter chain when said cutter chain guide is in the aforementionedposition of tangency.

13. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide, a cutter chain movable along said guide at a levelsubstantially tangent to the circular paths of said rotatable cutters,the improvement in such machine comprising auxiliary guide means forsaid cutter chain disposed at one end of said cutter chain guide, andmeans supporting said auxiliary guide means and operable to shift saidauxiliary guide means up and down with respect to said guide to vary thelength of the straight path of said cutter chain when said cutter chainguide is in the aforementioned position of tangency.

14. In a mining machine having a frame, cutters rotatable about parallelaxes and operative to cut bores in a seam of coal or the like, a cutterchain guide, a cutter chain movable along said guide at a levelsubstantially tangent to the circular paths of said rotatable cutters,the improvement in such machine comprising auxiliary guide means forsaid cutter chain disposed at one end of said cutter chain guide, saidauxiliary guide means being mounted upon an arm pivotally mounted inwardfrom said auxiliary guide means, and means for swinging said arm whenthe cutter chain guide is in the aforementioned position of tangency.

15. The invention as defined in claim 14, wherein strut means areinterposed between said frame and said arm to brace said arm in itslowered position.

References Cited in the file of this patent UNITED STATES PATENTS540,306 Fry a- June 4, 1895 1,210,925 French Jan. 2, 1917 1,371,224Campbell Mar. 15, 1921 1,603,621 McKinlay Oct 19, 1926 1,726,963McKinlay Sept. 3, 1929 1,808,649 Fleming June 2, 1931 1,978,526 EpplerOct. 30, 1934 2,374,240 Shankman Apr. 24, 1945 2,550,202 Robbins Apr.24, 1951 OTHER REFERENCES Coal Age, May 13, 1926, page 669. MiningCongress Journal, October 1938, McKinlay Entry Driving Machines, page70.

